All 2st plug gap question

pardon my ignorance all but what does the spark plug gap do/affect? i realize its the distance the spark has to jump but ive never 'gapped' any plug ive put in my bike. i just assumed they were set right from the factory & different plugs(sizes/types/heat ranges etc) had different gaps. i run the recommended ngk br8eg in my 2010 wr300 ungapped without drama. does it really make any difference-am i missing something? and how do you gap one?

The larger the gap the bigger the spark up until the point that the resistance is too high and it does not spark at all.

you stick a feeler guage in between the gap and measure it. bend the tang to spec which is something like .024"

caress with a mallet the best way to bend tang?

Or push it on the edge of your workbench. It bends easy. To gap it, stick a gapping tool / feeler guage in to the correct diameter. They are cheap at any auto parts store.

I bought 4 of this same plug for my wr165, and the gaps were all almost perfect out of the box FWIW...

my manual says a gap of 0.6-0.7 inches-i assume thats meant to be in mm which would equate to 0.024"-0.027"?! both ngk br8eg plugs are factory gapped at 0.53mm(0.021") & denso iridium at 0.6mm(0.024"). is it worth adjusting the ngk's you reckon & how would one go about it? cheers

yeah but how do you bend em out the correct way, my gaps on the ngks are too small?!

with the gapping tool that I was telling you about available at any auto parts store. Get a round one. It has a taper on it from small to large, and all the gaps written on the dial.

Instead of trying to explain it, here is a picture. Hopefully it's worth 1,000 words!

ahh i was blind but now i see. will suss one of these out, cant say ive ever seen one before. handy little tool. i thought you were just talking about normal feeler gauges-sorry bout that my bad, wasnt pickin up what you puttin down. thanks mate

No problem man! Glad i could help.